ConOptics, Inc. 19 Eagle Road, Danbury, CT 06810 Phone 800-748-3349 Fax 203-790-6145
Email: sales@conoptics.com, or visit www.conoptics.com
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Technical Overview:
The Model 25D has a maximum output of 175v p-p. The output stage is the only saturating part
of the amplifier. Although the amplifier accepts standard TTL drive levels as its input, the entire
amplifier with the exception of the output stage is linear. At the very input of the amplifier, a
switch allows the user to select either TTL or low level Analog as its required input format.
TTL Input: (Logic high >+2v, <+4.5v, Logic low <+.8v)
This input mode employs a S140 line driver as a buffer between the input signal entering the
system and the power amp. This allows the user some latitude on logic highs and lows at the
input. As the input section of the amplifier is linear, care must be taken not to drive this section
of the amplifier into saturation and cutoff. By virtue of an on-board line driver, the actual input
signals may be rather poor and still the internal line driving gate delivers the required signal to
the amplifier.
Analog Input:
This input mode is included to allow operation of the Model 25D with the Model 305
Synchronous Countdown. The Model 305 outputs a 0 to +1v, high-speed analog pulse which is
used to operate the Model 25D in the “Pulse-Picking” mode. The Analog input should only be
selected when driven by the Model 305.
Note:
For most applications the TTL input mode is selected. The only exception is when the Model
25D is configured with the Model 305 Synchronous Countdown for use as a Pulse Picker. In
either configuration the input impedance is 50 ohms.
All signal levels should be checked with an oscilloscope with the signal terminated
in 50 ohms before applying to the driver input.
Care should be taken when using a function generator or pulse generator as
output levels from these instruments can easily exceed the max Vih allowed for
the S140 buffer in the driver.
